In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not to be taken as an admission that the document, act or item of knowledge or any combination thereof was at the priority date:                (a) part of common general knowledge; or        (b) known to be relevant to an attempt to solve any problem with which this specification is concerned.        
Diesel oil, due to its cost and availability, continues to be the backbone for industry around the world being the principal fuel for use in truck, ships, trains, some cars and other automotive equipment and different stationary types of engines.
It is recognised that the combustion of diesel fuel in engines can be hazardous to the environment. In particular, the partial combustion of diesel fuel to carbon-based particulates, hydrocarbons and carbon monoxide creates noxious black exhaust gases while the additional problem of nitrogen oxide production adds to the pollution. This is particularly observable in trucks and other automotive vehicles where noxious black exhaust gases can be seen as they are released from the vehicle exhaust into the environment.
Attempts have been made over the years to address the environmental concerns associated with exhaust fumes from engines by using alcohols such as methanol or ethanol as fuels. Such attempts, for instance, have established that 15% ethanol and 85% diesel oil provides a fuel of acceptable burning capacity without the necessity of modifying existing diesel engines.
The problem with using ethanol or methanol as a fuel in conjunction with diesel oil is that ethanol and methanol are immiscible with diesel oil within the normal range of operating temperatures, that is, they cannot be uniformly mixed or blended into one phase without rapid separation into their component parts.
One attempt to address the immiscibility problem involved mixing diesel fuel, a C3 (excluding n-propanol)-C22 organic alcohol and either (i) ethanol and/or n-propanol or (ii) a mixture of two or more of methanol, ethanol and n-propanol. Another attempt tried mixing diesel fuel, up to 20% ethanol or n-propanol and up to 15% of a fatty acid and/or organic ester.
However the presence of a significant water content may cause separation of the alcohol and diesel fuel. Water can enter into the fuel in a number of ways. These include (i) absorbing water from the air, (ii) the alcohol often having some intrinsic water content, and (iii) diesel fuel picking up water from the refinery pipes which are usually flushed with water.
Water also forms a constant boiling azeotrope with ethanol. Further attempts to remove the water fail by distillation. Even if substantially dehydrated ethanol is prepared, it is very hygroscopic and will quickly absorb moisture from the atmosphere unless subjected to special storage techniques.
One attempt to address the water content problem involved the use of a surfactant system comprising N, N-dimethylamine and a long chain fatty acid substance in a hybrid fuel microemulsion containing diesel fuel, water and alcohol. These trials further concluded that the advantage provided by N,N-dimethylamine could not be extrapolated to all amine compounds because in a comparative trial 2-amino-2-methyl-1-propanol was substituted for N,N-dimethylamine and the substituted formulations were not water tolerant to the same low temperatures.
A second attempt involved using an ethoxylated fatty alcohol and/or its reaction product with an amide as a stabilising additive. A third attempt involves using a polymeric fuel additive formed by reacting together an ethoxylated alcohol and a fatty alkanolamide.
There is therefore a need for fuel blends which are more water tolerant, especially at lower temperatures.